By using ‘In Front’, Blender draws your retopo Object always in front of everything else.You’ll hqve to un-check that.
Now, however the retopo ‘sinks’ partially into the target Mesh. If you don’t like that, you can change the settings of your Shrinkwrap Modifier (I am assuming that that is the Modifier you are using, if not, add it) to be Outside of your target, with some Offset:
